Iranian rules stipulate women shown on Iran's state television should have a hijab that covers their hair, arms and legs, making the Oscars quite a challenge.

The rules do vary somewhat for foreigners, and in particular state dignitaries and celebrities.

Doctored? ... the image of the jet released by an Iranian state news agency. Photo: Khouz News

A foreign woman travelling inside Iran should comply with the same restrictions on Iranian women, but those shown on TV can get away with not wearing the hijab.

Obama wore a Naeem Khan dress which had a scoop neckline and mid-width shoulder straps.

Two weeks ago, Khouz News released a picture of a new radar-dodging stealth fighter jet flying above snow-covered mountains.

But the picture was immediately suspected to be a fake, with the lighting on the plane and its position similar to its appearance in pictures on the ground in Tehran.

It was also revealed that the background image of the mountain was taken from the stock image site PickyWallpapers.com.

In 2008, news wire Agence France-Presse had to retract an official image of an Iran missile launch following revelations it was doctored to include an extra missile. The photo had appeared on the front pages of many media outlets including NYTimes.com and the front page of The Los Angeles Times.

In November 2012 Iran showed off a new drone design, but it was later revealed that the photographs it released were ripped off from a Japanese university and doctored.